A father and son construction team were killed instantly when a lightning bolt hit a metal pipe on a building site. A young couple on a date was also hit, with an 18 year-old man dying on the spot, while his girlfriend has been hospitalized in serious condition.

The rain lasted less than half an hour, but flooded more than a dozen streets.

Moscow had suffered a whole week of tropically hot weather with none of the evening storms typical for the season. Then, on Friday 13th the heavens opened at once, with lightning striking several times in quick succession.

The rain caused chaos on the most prestigious streets of the city. Car owners scampered to save their cars from the torrents that flowed down from the higher city hills. Several eyewitness videos show cars being carried helplessly by the torrent. Waiters from luxury cafes quickly cleared the tables on the terraces of luxury roadside cafes, and passers-by cowered underneath building marquees.

Meteorologists warn that further storms were possible throughout the weekend.